Power driven tool



Q Nov. 5, 1940. E. AMUNDSEN 2,220,195

POWER DRIVEN TOOL Filed May 9. 1938 ATTORNEYS Patented Nov. 5, 1940 UNITED STATES PATENT OFFICEv 2,220,195 I V Y POWER DRIVEN TOOL Ernest Amundsen, New York, N. Y. I

Application'May 9, 1938, Serial No. 206,960

2 Claims.

This invention relates to power driven tools and more particularly it pertains to power driven tools of the hand type.

One object of the present invention is to improve the construction and mode of operation of power driven hand tools and to provide such tools with mechanisms which will effect a better operation than such prior machines with which I am familiar.

A feature of the present invention consists in the provision in a machine of the character above outlined, of novel means for adjusting the force of the impact imparted to the tool when it is in operation.

Another feature of the invention consists in the provision of novel means for mounting the tool in position for operation.

Another feature of the invention resides in a novel construction for adjustably mounting the tool with respect to the operating means thereof.

Still another feature of the invention resides in the provision of a renewable impact element for the impact hammer.

Still another feature of the invention resides in the provision of means operating in combination with the tool mounting means for limiting in both directions, sliding movement of the tool and for cushioning its sliding movement in one direction.

Other features of the invention relate to certain novel and improved constructions, arrangements and combinations of parts hereinafter described and particularly pointed out in the claims, the advantages of which will be readily understood and appreciated by those skilled in the art.

The invention will be clearly understood from the accompanying drawing illustrating the invention in its preferred form and the following detailed description of the constructions therein shown.

In the drawing:

Figure 1 is a perspective view of a hand tool constructed in accordance with the present invention,

Figure 2 is a longitudinal sectional view on an enlarged scale, and; I

Figure 3 is a detail sectional view taken substantially on the line 33 of Figure 2.

'50 In the present embodiment of the invention,

5 ing which is of the shape illustrated in Figure 1 and which is secured to the housing of the motor 5 by means of bolts or the like 8.

Carried by two arms 9' and I0, there is a housing 9 which is of tubular form, the same being secured to the arms 9' and ID as indi- 5- cated at the points I0 and II respectively in the drawing. The arm 9 is secured to the motor 5, by bolts or the like 8. The tubular housing 9 has each of its ends internally screw threaded as indicated by the reference characters I2 10 and I3.

Mounted within the tubular housing 9 and adapted for reciprocal movement therein, there is a hammer I5. The hammer I5 is reciprocated in one direction by the electric motor and in the other direction by energy stored in a coil spring l6. Connected to the motor shaft 6, there is a worm I! which drives a worm gear [8, carried by a shaft IS. The shaft 19 is rotatably mounted in a bearing 20 which is preferably "20 formed in the end of the arm Ill heretofore mentioned. The inner end of the shaft l9 extends beyond the inner face of the worm gear I8 and keyed to this extended end of the shaft l9, there is a cam 2|. As the shaft [9 is rotated by the 25 electric motor, the cam is rotated and it is, by rotation of the cam 2|, that the hammer I5 is reciprocated in one direction. The shaft I9 is retained in position in the bearing 20 by means it of the cam 2| and a collar 22, the' latter being 30 secured to the outer end 23 of the shaft l9 which outer end extends beyond the end of the bearing 2|] as shown in Figure 2. The cam 2| has a gradually rising cam face 24 which ends abruptly as at 25, as best illustrated in Figure 3, and "35 the manner in which this construction operates will be hereinafter more specifically described.

Threaded into the internal threaded end ID of the tubular housing 9, there is an adjusting member 26, which has a reduced end 21 and the 10 adjacent end of the hammer I5 is reduced as at 28. The coil spring [6 heretofore mentioned is interposed between the adjusting member 26 and the adjacent end of the hammer l5 and its ends embrace the reduced ends 21 and 28 respectively 45 of the adjusting member 26 and the hammer l5.

The reference numeral 21 designates a crosspin which is secured to the hammer 15 by means of a set screw or the like 28'. The tubular housing 9 is cut out as at 29 to provide slots in which the cross-pin 21' operates during reciprocation of the hammer l5 in the tubular housing 9. The inner end of the cross-pin 21'is extended beyond the adjacent wall of the housing and carries a roller 30 for engagement by the cam 2| heretofore mentioned.

From the foregoing it will be apparent that as the electric motor 5 is operated, through the medium of the worm l1 and worm gear I8, the shaft l9 and the cam 2| will be rotated. As the cam 2| is rotated, in a clock-wise direction, as in Figure 3, the roller 30 rides the cam face of the cam, moving the hammer l5 upwardly in the drawing. Upward movement of the hammer |5 places the coil spring I6 under compression and as the roller passes off the abrupt end or shoulder 25 of the cam face 24 of the cam 2|, the hammer is released to the action of the coil spring which forcibly propels the hammer 5 downwardly in the drawing until the roller 30 engages the hub 32 of the cam 2|. Continued rotation of the shaft l9, therefore, produces a reciprocating movement of the hammer I5 in the tubular housing 9, the hammer being reciprocated in one direction by means of the driven cam 2| and in the other direction by the energy stored in the coil spring 6 when the hammer is reciprocated against the action of the same by the cam 2|. The extent to which the coil spring is placed under compression when the hammer is moved by the cam may be determined by adjustment oi the member 26.

The impact of the hammer when operated by the coil spring i9 is transmitted to a tool which is herein illustrated as a chisel 35 although, tools of other types than chisels may be obviously employed,and I will now describe the manner in which the tool is moved by the impact transmitted thereto.

The opposite end of the piston or, the lower end as illustrated in the drawing, is recessed as at 36 and maintained in this recess, there is an impact member. The impact member has a head 31 which engages the end of the hammer I5 and a stem 38 which projects into the recess 36. An inclined face 39 on the side of the stem 38 of the impact member provides a shoulder 40 and passing through a slot 4| in the tubular housing 9, there is a set screw 42 which engages the inclined face 39 and the shoulder 49 to retain the impact member in position relative to the hammer.

The reference numeral 44 designates a sleeve bushing. This sleeve bushing has an external .ed engagement with the internal thread 46 of the sleeve bushing 44. The tool 35 is keyed to the bearing 49 in such a manner'that it may reciprocate in said bearing but is non-rotatable therein, the means by which this is accomplished being indicated in Figure 2 of the drawing as comprising a rib or projection 5| carried by the bearing 49 and projecting into a channel or groove 52 in the tool.

Near its inner end, the tool 35 is provided with a flange 56 and interposed between the flange 56 and the inner end 57 of the bearing 49, there is a cushioning means 5s preferably in the form of a leather washer.

By this construction it is apparent that, al-

though the tool 35 has sliding movement in the bearing 49, this sliding movement is restricted in one direction by reason of engagement of the flange 58 with the inner end of the sleeve bushing 44 and in the other direction by engagement of the cushioning means 58 with the inner end of the bearing 49. This sliding movement permits of the inner end of the tool following closely the movement of the hammer |5 during operation of said hammer while the cushioning means 58 prevents undue vibration resulting from the impact transmitted to the inner end 48 of the tool.

As best illustrated in Figures 1 and 2, the tubular housing 9 extends to 'a point below the lower wall of the housing and carried by the extended end of the tubular housing 9, there is a handle 69. The handle has a portion 5| which embraces the extension of the tubular housing 9 and passing through the portion 6! and into engagement with the tubular housing 9, there is a set screw which forms the means for securing the handle 99 in position. i

Threaded engagement of the sleevebushing 44 with the internally threaded endof the housing 9 together with the threaded engagement between the bearing 49 and the sleeve bushing 44 permits of a fine adjustment of the toollrelative to the impact member of the hammer and permits of adjustment of the tool to an extension which will permit of engagement of the impact member of the hammer with the tool at any point between the extreme ends of the stroke of the hammer.

The tool operates in the following manner.,

is projected forwardly under theinfluence of the energy stored in the coil spring It. This movement of the hammer is transmitted'to the tool, through the impact member 38 and causes the same to perform a cutting operation since it is intermittently subjected to thisaction upon con- 1' tinued rotation of the cam 2|,

From the foregoing, it is apparent the present invention provides a new and improved power driven hand tool which is highly ef ficient in operation, economical to construct, and in which;

the objects of the invention have been carried out, and while I have shown certain embodiments of construction, it is to be understood'that the invention is not to be limited to the embodiments of construction herein shown and that the in-:

vention may be carried out in other forms without departing from the scope of-,,the appended claims.

Having thus described the invention, what i claimed as new, is: e

1. In a power operatedtool in combination with, a tubular housing, and an impact member mounted in said housing and having reciprocating movement therein, a toolretaine'r comprising a sleeve bushing threaded in one end of said housing for adjustment relative to the adjacent end of the impact member, a bearing sleeve threaded into said sleeve bushing, a'tool slidably mounted in said bearing sleeve, and means for limiting the sliding movement of said tool in said bearing sleeve, said means comprising a flange carried by the tool and adapted to engage the inner end. of the bearing sleeve to limit the sliding movement of the tool in one direction and adapted to engage the inner end of the sleeve bushing to limit sliding movement of the tool in the opposite direction.

2. In a power operated tool in combination with, a tubular housing, and an impact member mounted in said housing and having reciprocating movement therein, a tool retainer comprising a sleeve bushing threaded in one end of said housing for adjustment relative to the adjacent carried by the tool and adapted to engage the inner end of the bearing sleeve to limit the sliding movement of the tool in one direction and adapted to engage the inner end of the sleeve bushing to limit sliding movement of the tool in the opposite direction, and means for cushioning the sliding movement of the tool in one direction.

ERNEST AMUNDSEN. 

